Remote volume control device for radio receiving sets



Nov. 8, 1938. H. K. TODD 2,135,739

REMOTE VOLUME CONTROL DEVICE FOR RADIO RECEIVING SETS Filed Aug. 27, 1957 INVENTOR ATTORN EY Patented Nov. 8, 1938 UNiTED STATES REMOTE VOLUME CONTROL DEVICE FOR- RADIO RECEIVING SETS Harry K. Todd, Tacoma, Wash.

Application August 27,

2 Claims.

The present invention relates to radio volume control of the type shown and described in my co-pending application, Serial Number 129,196, filed March 5, 1937, of which the present application is a continuation in part.

The invention primarily aims to provide a remote control device for controlling the volume of the sound of a radio receiving set and has for its primary object the incorporation in a device of this character of an automatic take-up reel whereby the device may be self-contained in the radio cabinet, but may be instantly withdrawn and operated from a remote point.

An important feature of the invention resides in the provision of a volume control device for radio receiving sets, adapted to be manipulated by the listener at a point distant from the radio receiving set to cut down the sound volume and restore the same to its full strength whenever desired.

It is also an important feature of the invention to provide a remote control device mounted on a radio set and having means capable of being withdrawn to a point away from the set whereby said device may be manipulated to regulate the radio sound volume.

The invention further contemplates the provision of a device of the character mentioned associated with the means supplying theelectrical current to the radio receiving set, whereby the intensity of the current may be varied for controlling the sound volume.

Other important objects and advantages of the invention will be in part obvious and in part pointed out hereinafter.

In order that the invention and its mode of operation may be readily understood by persons skilled in the art, I have, in the accompanying drawing and in the detailed description based thereupon, set out a possible embodiment of the invention.

In this drawing Figure 1 is a front elevation of a radio set embodying the invention.

Figure 2 is a face elevation of the reel with a portion broken away.

Figure 3 is a partial vertical section through the reel.

Figure 4 is a diagrammatic illustration of the electric circuit.

Having more particular reference to the drawing wherein like characters of reference will designate corersponding parts throughout, I have shown a radio cabinet I which, of course, may be of any suitable design or construction, and which encloses a radio set 2 and a loud speaker 3. The radio set 2 is provided with the usual control 4 adapted to be manipulated to increase or decrease the sound volume.

Electrical current is supplied to the radio re- 1937, Serial No. 161,219

ceiving set for operation thereof through a circuit 5 consisting of a positive lead 6 and a negative lead 1. In accordance with the invention, a resistance element 8 is interposed in the electrical circuit 5 and is intended to be cut into or out of the circuit by actuation of specially devised means, the construction and operation of which will be presently described.

Preferably mounted on one side of the radio cabinet I is a reel} which may be of any suitable well known construction and, in the present instance, the basic construction of the reel shown in the drawing is that disclosed in the patent to one Neil S. Cameron, dated October 19, 1915, No. 1,157,505, certain modifications having been made to adapt the Cameron reel to this invention.

As represented, the reel 9 comprises a housing Ill having a flange l l disposed to snugly rest against the side panel of the radio cabinet I and secured thereto by means of bolts l2 orlike fastening elements. Enclosed within the housing is a pair of supporting plates l3 maintained in relative paralleling relation by means of spacing sleeves H! encircling the bolts l2 and having the opposite ends thereof abutting the inner surfaces of the respective plates. Formed in the plates I3 approximately centrally thereof are aligning openings and journalled in these openings is a drum i5 capable of rotation within the openings and having one end thereof projecting beyond the adjacent supporting plates as at l6.

The projecting end I6 of the drum is formed with an annular row of ratchet teeth ll. Disposed concentrically of the drum !5 and fixed to the latter adjacent the inner surfaces of the respective plates l3 are circular guides I8 for a dual I wire electrical cord [9 which is wound about the drum l5 and adapted to be withdrawn from the housing 16 through an opening 20 provided in the peripheral surface of said housing.

Surrounding the projecting end I8 of the drum i5 is a spring 2| having the inner convolution thereof fastened to the drum and the outer end secured to a pin 22 carried by the outer surface of the adjacent supporting plate l3.

Disposed in axial alignment with the end E6 of the drum I5 is a stub shaft 23 provided at its inner end with a plate 24 having the inner face formed with an annular row of teeth 25 designed to engage the teeth H on the adjacent end of the projected portion IE of the drum l5.

Surrounding the stub shaft 23 is a coil expan sion spring 26 acting to hold the teeth 25 in the plate in normal engagement with the teeth I? of the drum. The inner end of the stub shaft l3 carries a pair of pivoted levers 28 capable of relative swinging movement in a scissors fashion and having the outer end thereof formed to provide hand grips, the inner ends formed toprovide friction shoes engaging the outer surface of the housing II].

From the foregoing description, it will be understood that when the outer ends of the levers 28 are drawn towards each other, the shaft 23 is axially moved against the action of the spring 26 to withdraw the teeth 25 in engagement with the teeth [1, thus releasing the reel for a turning action by the spring 2| for Winding upon the reel the cord l9. It is, of course, to be understood that the design and coaction of the teeth I! with the teeth 25 is such that the cord may be withdrawn from the reel and the reel held in any of its adjusted positions so that upon operation of the levers 28, the reel may again wind the cord for enclosing the same Within the reel casing. I

The other end 29 of the drum l5 projects for a distance beyond the adjacent supporting plate I 3 and into the radio cabinet I which, for that purpose, is formed with an opening 38. A plate 3| of insulating material is rigidly secured to said end 29 to rotate therewith and has fixed thereto a pair of concentric contact rings 32a and 321) respectively.

Supported within the radio cabinet, preferably by means of a yoke 33, are pairs of brushes 34 and 35 respectively, one brush of each pair engaging each contact ring. One of the brushes 34 is connected to one of the wires l9a of the cord I 9, whereas one of the brushes 35 is connected to the other wire |9b of said cord.

The remaining brushes 34 and 35 are respectively connected to conductors 36 and 31, one conductor being topped on one side of the resistance element 8 interposed in the radio electrical supply circuit 5, and the other conductor 31 being topped on the other side of said element.

The free extremities of the cord wires |9a and |9b are connected to spring terminals 38 and 39 respectively, said terminals yieldably engaging each other so as to electrically connect the wires |9a and l9b. Thus it will be appreciated, by reference to Figure 4, that the current passes along the lead 6, the conductor 38, the brush 34, the ring 32a, the wire I9a, the spring terminal 38, the spring terminal 39, the wire l9b, the ring 32b, the brush 35, the conductor 31, and the lead 1, thereby shunting out of the circuit the resistance element 8.

Accordingly, the current will directly pass into the radio set around the resistance element 8 so that the sound emitted by the radio will have its maximum volume. After interruption of the circuit by separation of the spring terminals 38 and 39, the current will be forced to pass through the resistance element 8, whereby the amount of current will be reduced to the extent that the sound volume will be lowered so as to be but slightly audible.

The terminals 38 and 39 may be separated in any desired manner but, for the purpose of illustration, I have shown a plunger 40 having a spear-shaped head 4| adapted to be wedged between the spring terminals for separating the same. For this purpose, the head 4| is constructed of insulating material. The plunger 40 terminates with a button 42 by means of which said plunger may be forced towards the spring terminals 38 and 39 in opposition to a coil spring 43 associated with the plunger.

When the button 42 is depressed against the action of the spring 43, the head 4| will be forced between the spring terminals 38 and 33 and thus the circuit including the conductors 38 and 3'! and wires |9a and I9!) will be broken for reducing the amount of current flowing through the resistance element 9.

Upon release of the button 42, the spring 43 will force the head 4| out of engagement with the terminals 38 and 39 and, as a result, the continuity of the circuit is again established for shunting the current around the resistance element 8, thereby enabling the radio receiving set to function at full sound volume.

Due to the fact that the current supply to the radio set is never interrupted, it will be appreciated that the heating of the tubes is not interfered with and, therefore, the radio receiving set will emit sound at full volume immediately upon releasing the plunger 40.

Whereas I have described the reel 9 as being mounted on the outside of the radio cabinet, it will be understood that the reel may be placed within the cabinet which may then be formed with an opening sufiicient to expose the brake releasing levers 28. I

As already stated, the reel may be of various constructions and, in this connection, I wish to call attention to the fact that I have found that a reel constructed in accordance with the ordinary curtain or shade roller principle will Work satisfactorily.

Obviously, other modifications in the construction and embodiment of the invention may be made without departing from the gist thereof, and, accordingly, any modifications coming Within the scope of the sub-joined claims are to be considered within the spirit of the invention.

What I claim is:

1. In combination, a radio cabinet; 9. radio set arranged therein; an incoming current supply circuit for said radio set; a resistance element arranged in one of the conductors of said circuit; a take-up reel rotatably supported by the cabinet; a pair of contact rings carried by said reel; brushes electrically bearing upon said rings; leads connecting said brushes to one of the conductors of said circuit to opposite sides of said resistance element; an electric cord wound around said reel and including a pair of wires each electrically connected respectively to said contact rings; clips connected to the ends of said wires and normally engaging each other; and a manually operated element for separating said clips for the purpose set forth.

2. In combination, a radio cabinet; a radio set arranged therein; an incoming current supply circuit for said radio set; a resistance circuit interposed in said electric supply circuit; a takeup r'eel rotatably supported by said cabinet; a pair of contact rings carried by said reel; brushes electrically bearing upon said rings and electrically associated with said resistance circuit; an electric cord wound around said reel and including a pair of wires, each electrically connected respectively to said contact rings; contact clips connected to the ends of said wires and acting to establish an electrical connection between the latter; and a manually operated element for controlling the action of said clips for the purpose set forth.

HARRY K. TODD. 

